The proposed conference focuses on the signal transduction function of the placenta. Trophoblast cells coordinate the activities of maternal and embryonic tissues by secreting hormones, cytokines and various growth factors that selectively and specifically gain access to maternal and embryonic compartments. The trophoblast cell signalling system is essential for the coordinated development of various embryonic and maternal tissues. Abnormalities associated with trophoblast cell growth, differentiation, or function result in impaired embryonic development of spontaneous abortion. Internationally recognized developmental and cell biologists as well as molecular endocrinologists interested in the biology of trophoblast cells will participate in the conference. The objectives of the meeting are to: 1) provide a forum for current research on trophoblast cell biology and endocrinology; 2) bring together cell and developmental biologists and molecular endocrinologists interested in trophoblast cells; 3) bring together individuals working with trophoblast cells of different species. The meeting will be held from August 6-9, 1992, in Park City, Utah, and is sponsored by Serono Symposia, USA. We are requesting funds to assist with the expenses of bringing twelve additional participants to the conference. This request to the NIH is largely to ensure the presence of a diverse group of scientists interested in trophoblast cells at the conference. Serono will assume the financial responsibilities for twenty of the more senior and established investigators. We are requesting that the NIH provides financial assistance that will enable greater participation by more junior investigators. Inclusion of these individuals will help increase the diversity of ideas exchanged at the conference.